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Remove an entire column from a data.frame in R
...=4:6)
to remove just the a column you could do
Data <- subset( Data, select = -a )
and to remove the b and d columns you could do
Data <- subset( Data, select = -c(d, b ) )
You can remove all columns between d and b with:
Data <- subset( Data, select = -c( d : b )
As I said above...
Emacs on Mac OS X Leopard key bindings
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⌘ + → - move to end of current line
Shift + any of the above extend selection by appropriate amount
Click then drag - select text
Double-click then drag - select text, wrapping to word ends
Triple-click then drag - select text, wrapping to paragraph ends
Shift + Select text with mouse - add...
Reading CSV files using C#
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Surely a char-based approach is more natural for this sort of problem than a regex. Depending on the presence of quotation marks the behavior is supposed to be different.
– Casey
May 9 '16 at 1:...
Fix code indentation in Xcode
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Before Xcode 9 (for Xcode 9 see default shortcut below)
select text
right-click
there's a "Re-indent selection" item in popup menu
In XCode 4 there is one more step:
select text
right-click
Click on "Structure"
there's a "Re-indent selection" and other options in popup men...
Javascript Equivalent to C# LINQ Select
...always add custom methods to the array prototype as well:
Array.prototype.select = function(expr){
var arr = this;
//do custom stuff
return arr.map(expr); //or $.map(expr);
};
var ids = this.fruits.select(function(v){
return v.Id;
});
An extended version that uses the function ...
How to set Sqlite3 to be case insensitive when string comparing?
I want to select records from sqlite3 database by string matching. But if I use '=' in the where clause, I found that sqlite3 is case sensitive. Can anyone tell me how to use string comparing case-insensitive?
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How do I get list of all tables in a database using TSQL?
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SQL Server 2000, 2005, 2008, 2012, 2014, 2016, 2017 or 2019:
SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE='BASE TABLE'
To show only tables from a particular database
SELECT TABLE_NAME
FROM <DATABASE_NAME>.INFORMATION_SCHEMA.TABLES
WHERE TABLE_TYPE = 'BASE TABLE'...
Finding duplicate rows in SQL Server
...abase of organizations, and there are many duplicate rows. I want to run a select statement to grab all of these and the amount of dupes, but also return the ids that are associated with each organization.
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How to paste text to end of every line? Sublime 2
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Yeah Regex is cool, but there are other alternative.
Select all the lines you want to prefix or suffix
Goto menu Selection -> Split into Lines (Cmd/Ctrl + Shift + L)
This allows you to edit multiple lines at once. Now you can add *Quotes (") or anything * at start and end...
How can I remove the gloss on a select element in Safari on Mac?
On Macs and iOS devices, in Safari, a <select> element with a background color generates a gloss over itself. This does not seem to happen in other operating systems.
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